Messages in this thread | | | Date | Wed, 31 Aug 2005 21:34:16 +0200 (CEST) | From | Roman Zippel <> | Subject | Re: [Linux-fbdev-devel] [PATCH 1/1 2.6.13] framebuffer: bit_putcs() optimization for 8x* fonts |
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Hi,
On Wed, 31 Aug 2005, Knut Petersen wrote:
> I added the multiply back because gcc (v. 3.3.4) does generate the fastest > code > if I write it this way.
The multiply is not generally faster, so your version may be the fastest, but in other situations it will be a lot slower. My version is generally fast.
> The special case for s_pitch == 2 saves about 270 ms system time (2120 -> > 1850ms) > with a 16x30 font.
Compared to what? How much is the function call overhead?
> It´s as fast/slow as your previous version, the measurements are almost > identical.
The generated code is a bit smaller, so it mostly depends on the icache to see a difference.
bye, Roman | |